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-rw-r--r--drivers/hid/hid-input.c80
-rw-r--r--include/linux/hid.h1
2 files changed, 80 insertions, 1 deletions
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 7480799e535..308eee8fc7c 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1137,6 +1137,74 @@ unsigned int hidinput_count_leds(struct hid_device *hid)
}
EXPORT_SYMBOL_GPL(hidinput_count_leds);
+static void hidinput_led_worker(struct work_struct *work)
+{
+ struct hid_device *hid = container_of(work, struct hid_device,
+ led_work);
+ struct hid_field *field;
+ struct hid_report *report;
+ int len;
+ __u8 *buf;
+
+ field = hidinput_get_led_field(hid);
+ if (!field)
+ return;
+
+ /*
+ * field->report is accessed unlocked regarding HID core. So there might
+ * be another incoming SET-LED request from user-space, which changes
+ * the LED state while we assemble our outgoing buffer. However, this
+ * doesn't matter as hid_output_report() correctly converts it into a
+ * boolean value no matter what information is currently set on the LED
+ * field (even garbage). So the remote device will always get a valid
+ * request.
+ * And in case we send a wrong value, a next led worker is spawned
+ * for every SET-LED request so the following worker will send the
+ * correct value, guaranteed!
+ */
+
+ report = field->report;
+
+ /* use custom SET_REPORT request if possible (asynchronous) */
+ if (hid->ll_driver->request)
+ return hid->ll_driver->request(hid, report, HID_REQ_SET_REPORT);
+
+ /* fall back to generic raw-output-report */
+ len = ((report->size - 1) >> 3) + 1 + (report->id > 0);
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf)
+ return;
+
+ hid_output_report(report, buf);
+ /* synchronous output report */
+ hid->hid_output_raw_report(hid, buf, len, HID_OUTPUT_REPORT);
+ kfree(buf);
+}
+
+static int hidinput_input_event(struct input_dev *dev, unsigned int type,
+ unsigned int code, int value)
+{
+ struct hid_device *hid = input_get_drvdata(dev);
+ struct hid_field *field;
+ int offset;
+
+ if (type == EV_FF)
+ return input_ff_event(dev, type, code, value);
+
+ if (type != EV_LED)
+ return -1;
+
+ if ((offset = hidinput_find_field(hid, type, code, &field)) == -1) {
+ hid_warn(dev, "event field not found\n");
+ return -1;
+ }
+
+ hid_set_field(field, offset, value);
+
+ schedule_work(&hid->led_work);
+ return 0;
+}
+
static int hidinput_open(struct input_dev *dev)
{
struct hid_device *hid = input_get_drvdata(dev);
@@ -1183,7 +1251,10 @@ static struct hid_input *hidinput_allocate(struct hid_device *hid)
}
input_set_drvdata(input_dev, hid);
- input_dev->event = hid->ll_driver->hidinput_input_event;
+ if (hid->ll_driver->hidinput_input_event)
+ input_dev->event = hid->ll_driver->hidinput_input_event;
+ else if (hid->ll_driver->request || hid->hid_output_raw_report)
+ input_dev->event = hidinput_input_event;
input_dev->open = hidinput_open;
input_dev->close = hidinput_close;
input_dev->setkeycode = hidinput_setkeycode;
@@ -1278,6 +1349,7 @@ int hidinput_connect(struct hid_device *hid, unsigned int force)
int i, j, k;
INIT_LIST_HEAD(&hid->inputs);
+ INIT_WORK(&hid->led_work, hidinput_led_worker);
if (!force) {
for (i = 0; i < hid->maxcollection; i++) {
@@ -1379,6 +1451,12 @@ void hidinput_disconnect(struct hid_device *hid)
input_unregister_device(hidinput->input);
kfree(hidinput);
}
+
+ /* led_work is spawned by input_dev callbacks, but doesn't access the
+ * parent input_dev at all. Once all input devices are removed, we
+ * know that led_work will never get restarted, so we can cancel it
+ * synchronously and are safe. */
+ cancel_work_sync(&hid->led_work);
}
EXPORT_SYMBOL_GPL(hidinput_disconnect);
diff --git a/include/linux/hid.h b/include/linux/hid.h
index b8058c5c559..ea4b828cb9c 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -456,6 +456,7 @@ struct hid_device { /* device report descriptor */
enum hid_type type; /* device type (mouse, kbd, ...) */
unsigned country; /* HID country */
struct hid_report_enum report_enum[HID_REPORT_TYPES];
+ struct work_struct led_work; /* delayed LED worker */
struct semaphore driver_lock; /* protects the current driver, except during input */
struct semaphore driver_input_lock; /* protects the current driver */